Recently, the optical imaging field has been rapidly expanding in scope through the use of new exogenous molecular probes. We have already developed a multi-frequency &multi- spectral optical tomography animal imaging system and integrated to an MRI system. In this application, we will expand our hybrid system to measure dynamic information from exogenous probes. This system would measure the enhancement kinetics of the bi-functional MR/NIR or mono-functional NIR contrast agents in addition to the endogenous contrast due to hemoglobin contents and scattering properties. There are two main phases of the proposal. The first and the foremost phase is the technology development, which can be classified into two sub aims: a) the development of a novel multi-modality dynamic imaging system and b) the development of polymer based bi-functional and mono-functional NIR agents. We believe that such a hybrid system will facilitate the development of new contrast agents for biomedical imaging and that the development of polymer based molecular agents will provide a potential new molecular platform for these new contrast agents. In the second phase of the proposal, we will try to utilize this novel hybrid system together with a small molecular MR and a medium size (~30-40 kDa) novel polymer based optical agent. We will compare the role of all kinetic parameters and intrinsic properties obtained by MR/Optical imaging system, individually or combined, in cancer diagnosis after completing all analysis steps. Thus, we will be able to test our hypothesis that "the parameters obtained by macromolecular optical agent together with total hemoglobin, oxygen saturation and tissue scattering parameters can achieve a higher specificity in differentiating between ENU induced malignant and benign tumors compared to MRI parameters measured by low molecular weight extracellular MRI agents". We believe our collaboration with GE Global Research Center for the development of the novel MR/NIR contrast agents will serve to close the gap between the academia and the industries further for biomedical imaging applications. If successful, the outcome of our effort will offer a sophisticated tool that could provide high sensitivity and high specificity in the detection and characterization of tumors. With appropriate modifications in design, the proposed MR/Optical technology has a great translational potential for future human clinical trials. This application is aimed at developing a hybrid MR/DOT system along with novel polymer based contrast agents. If successful, the outcome of our effort will offer a sophisticated tool that could provide high sensitivity and high specificity in the detection and characterization of tumors.